more than one usbserial

Hello,

What do you think how would it be possible to create more than one serial USB connection through the native USB?

I'm not sure to understand your question.

The Native USB port is USB 2.0 compliant HS, FS and LS with 10 endpoints. When a DUE acts as a USB Host, you can connect either a single device as a USB Device (e.g. a web cam with cam + microphone or a USB Memory stick), or several USB Devices througout a USB Hub 2.0. Obviously you'll have to remain under its processing/SRAM/UOTGHS dedicated RAM capabilities vs USB Devices requirements.

Be aware that the hard point with USB protocol is its relative complexity. If you can't find a public library for a specific USB Device (video, audio, Mass storage, ....) You'll have to learn how to enumerate a Device, select a Device configuration and finally leverage this specific Device. This is definitely not a beginner's project.

Due would act as a USB device and provides more than one USB serial so it would appear as /dev/ttyACM0, ACM1 in Linux, and I would access it as USBSerial0,1 from my arduino code.